v3.25.2
Financial Risks - Summary of Breakdown of Wholesale Receivables and Dealer Loan Receivables (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2025
Mar. 31, 2024
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan ¥ 17,638,825 ¥ 19,488,811
Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 17,214,236 19,132,321
Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 411,202 330,243
Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 13,387 26,247
Performing [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 4,478,021 4,741,270
Performing [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 4,478,021 4,741,270
Credit Watch [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 357,379 193,799
Credit Watch [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 213,400 61,078
Credit Watch [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 143,979 132,721
At Risk [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 56,776 49,489
At Risk [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 54,774 45,231
At Risk [Member] | Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 2,003 4,258
Default [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 10,360 21,209
Default [Member] | Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 10,360 21,209
Loan commitments [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 10,477,894 11,245,712
Loan commitments [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 10,288,422 11,129,604
Loan commitments [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 188,448 115,327
Loan commitments [Member] | Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 1,024 781
Financial guarantee contracts [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 2,258,395 3,237,333
Financial guarantee contracts [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan 2,234,393 3,200,368
Financial guarantee contracts [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loan ¥ 24,001 ¥ 36,964